The Sundance Film Festival has an apparent record lineup of female directors competing for its top honour this January.

Half the entries - eight of the 16 films - announced Wednesday in the festival's US dramatic competition were directed by women for the next installment of Robert Redford's independent-cinema showcase.

The festival runs from January 17 to 27 in Park City, Utah.

Going back to 1992, the best showing previously for female filmmakers was in 2000, when six of the 16 US dramatic contenders were directed by women.

Sundance organisers were still trolling back to the early years of the festival's 33-year history, but this January's eight competition films appears to be most ever from women and the first time the entries have been evenly split between female and male directors.

Among the competition films from female filmmakers are:

- Francesca Gregorini's Emanuel and the Truth About Fishes, whose cast includes Jessica Biel and Frances O'Connor in the story of a troubled girl fixated on a mysterious neighbour.

- Liz W. Garcia's The Lifeguard, with Kristen Bell as a reporter who moves home to Connecticut and takes a job as a lifeguard.

The festival's US dramatic lineup also features the first Sundance entry for Harry Potter star Daniel Radcliffe, who stars as Allen Ginsberg in director John Krokidas' Kill Your Darlings.

Male directors still dominate the big-screen, but the low-budget indie world has been narrowing the gender gap.

Sundance director John Cooper said some Sundance film categories have had a nearly even split between male and female directors in the past, a sign that more and more women are breaking into filmmaking.

"I think that's absolutely it," Cooper said.

"Also, what we've found is that through our short-film programs, they've been coming close to 50-50 in certain years or at least a high level of women directors.

"So it's more of a coming-up-through-the-ranks situation" as female directors graduate from short films to feature-length stories.

- Martha Shane and Lana Wilson's After Tiller, profiling doctors providing late-term abortions after the murder of a colleague by an abortion opponent.

- Gabriela Cowperthwaite's Blackfish, which explores the consequences of captivity for killer whales, one of which was involved in the deaths of three people.

The opening-night film for the US documentary lineup is Morgan Neville's Twenty Feet From Stardom, a portrait of pop music's generally anonymous backup singers. On the world-cinema front, the opening-night dramatic entry is Chilean director Sebastian Silva's Crystal Fairy, with Michael Cera and Gabby Hoffmann in a South American road trip adventure, while the opening documentary is British filmmaker Marc Silver's Who Is Dayani Cristal?, chronicling the search for the identity of an anonymous body found in the Arizona desert.

Sundance announces its lineup of premieres featuring bigger-name stars and filmmakers on Monday.